Enonic version: CMS 4.7 / XP 7.x

In the process of migrating from 4.7 to XP7, we haven’t (yet) “dared” to run the cms2xp-script directly towards the 4.7 prod-database (we have instead exported/imported it into a temporary db).
This is quite time-consuming, though…

The script-documentation explains:
“…… It also needs direct connection access to the database where the CMS data is stored. The CMS itself does not need to be running.”

But - what happens if we execute the migration script towards the 4.7 production database, while CMS is running?
Will the script affect the system in any way, will the database be loaded with traffic?
Would you recommend, or advise against, running directly towards production?